The battle to get ENDA passed during the current session of Congress has been long and protracted, with the legislation receiving bursts of media attention that punctuate long waiting periods. Reid's attempt to set up a cloture vote — which would prevent an attempted filibuster that could kill the bill — brought the most recent flurry of updates. But if you haven't been following the bill closely, the sudden surge in ENDA mentions could be a little disarming.

ENDA is an acronym for the Employment Non-Discrimination Act, a bill intended to prohibit discrimination based on sexual orientation or gender identity in hiring and employment. As it reads now, the legislation would apply to civilian employers with at least 15 employees -- although there are some exceptions that we'll get to later.

The recent form of ENDA was introduced in April 2013 by two Democrats in Congress, Colorado Rep. Jared Polis and Oregon Sen. Jeff Merkley.

2. These protections don't already exist?

Not on a national level, no. And that's not for lack of trying. A bill with the ENDA name has been introduced in nearly every Congress since 1994 (the exception is the 109th Congress, which governed in 2005 and 2006).

But attempts to pass the legislation haven't been successful. In the previous nine Congress sessions during which ENDA was introduced, the bill has come to a vote only twice. Most recently, in 2007, the bill was approved in a Democrat-controlled House of Representatives on a 235-184 vote but stalled in a Democrat-led Senate. In 1996, the bill died in the Senate on a 50-49 vote after being introduced by Massachusetts Senator Ted Kennedy. In most of the other cases, ENDA hasn't made it out of committee or subcommitee.

That said, many states have started to fill in the gaps while national lawmakers debate the details over ENDA.

3. Oh, OK. So where do things stand for LGBT job applicants and employees?

At the moment, 21 states and D.C. offer protections that prohibit employment discrimination based on sexual orientation. Of those 21, only 17 states also prohibit employer discrimination based on gender identity. Most ENDA supporters point to the 33 states without legislation protecting transgender workers when discussing the potential impact of the bill.

There are a handful of asterisks on those numbers. At least 10 states have laws or administrative orders that protect public employees from discrimination based on sexual orientation and/or gender identity. Also, a handful of municipalities have passed local non-discrimination laws that go beyond what their states have passed.

4. And where does my state fit?

Well, our home state of Maryland is one of the four states that protects workers based on sexual orientation but not gender identity. The other three are Wisconsin, New Hampshire and New York.

Wisconsin, by the way, was the first state with an employment non-discrimination protection, passing its law in 1982. Geographically the states that have passed job discrimination bills follow similar patterns to marriage equality states: The entire Northeast region except Pennsylvania, a cluster in the western Great Lakes states (Minnesota, Iowa, Wisconsin and Illinois), the West Coast (Washington, Oregon, California) and some outliers in the Southwest (Nevada, Colorado and New Mexico).

Live in the South? Unless you're a public employee in Kentucky or Missouri, you're not protected by state laws.

5. If states have been passing these laws, why am I suddenly hearing about ENDA now?

6. If ENDA is supported by the majority of Americans, why do some oppose it?

Most opposition to ENDA comes from a coalition of conservatives that includes religious groups who say ENDA would violate their freedom of religion, libertarians who don't think the federal government should regulate private employers' hiring practices and Republican lawmakers who say that additional anti-discrimination protections are unnecessary.

One oft-cited argument by those groups is that ENDA would require businesses to provide opposite-sex access to bathrooms or locker rooms. This often gets dubbed "bathroom panic" by ENDA supporters, and it's been cited in a handful of state-level transgender rights laws.

By far the most common argument against ENDA right now cites "religious liberty." Some conservative groups say ENDA creates unmerited special protections for LGBT job applicants that would interfere with employers' abilities to follow their religious beliefs. Marriage equality often gets swept into this position, with some arguing that ENDA would force employers to provide partner benefits to same-sex spouses. (ENDA doesn't mention marital benefits.)

There's also a smaller group of vocal ENDA opponents who think the bill shouldn't pass because it seems pretty weak. ENDA's 2013 iteration includes a religious-exemption provision that some say is too far-reaching. Under the bill, religiously-affiliated organizations beyond school or houses of worship would be permitted to require employees and applicants to specific jobs adhere to a declared set of religious beliefs -- including ones that would prevent LGBT individuals from being employed. These groups are not currently permitted to use similar hiring practices when it comes to discrimination on the basis of age, race or sex.

6b. Wait, so some people think ENDA doesn't do enough to protect religious institutions, and others think it goes too far to protect them?

Yes, exactly.

Just know that the latter group is, for better or worse, a vocal minority. Many LGBT rights groups and politicians see the religious exemption as a compromise required to get support for ENDA from moderate Republicans. (That said, some argue that a similar approach is why transgender individuals don't have employment non-discrimination protections in Maryland.)

7. OK, got it. So what are ENDA's prospects for finally passing this year?

Well, if current counts are correct, ENDA could get approved by the Senate as early as Monday night. The bill has support from the Obama administration, with the president having written a blog post for The Huffington Post that encouraged legislators to approve the legislation. So ENDA is certainly gathering steam.

But even if the bill passes the Senate, it sill has to get through a Republican-controlled House of Representatives before it becomes a law. That looks to be a challenge, especially after House Speaker John Boehner's spokesman sent a statement to Politico Monday morning indicating Boehner's opposition to ENDA. As recent legislative fights have demonstrated, partisanship is fairly high in the House right now. So ENDA's success depends on how many moderate House Republicans are willing to break party lines and sign on to a bill with heavy Democratic support.

WASHINGTON -- A gay rights bill appears set to overcome a key Senate hurdle Monday, after a fifth Republican expressed support for the measure to prohibit workplace discrimination on the basis of sexual orientation or gender identity.

Gov. Larry Hogan may have sent a message of “tolerance and mutual respect” during his inauguration on Wednesday, but advocates for the state's lesbian, gay, bisexual and transgender community say his early actions in office have signaled something different.